Roller-grate.



E. P. STEVENS.

ROLLER GRATE.

APPLICATION FILED MAY 20, 1912.

1 l l l l I i I I i M .www

E. P. STEVENS.

ROLLER GRATE.

APPLIoATIoN FILED MAY zo, 1912.

1,127,939. Patented Feb.9,1915.

HBETS-SHEBT 2.

1HE MORRIS PETERS Lu rHuro'LlTHo WASHINGIDN, D C

E. P. STEVENS.

Patented Feb. 9, 1915.

3 SHEETS-SHEET 3.

i-HE MORRIS F'ErERS Co v PHOTO LITHU. WASHINL. fvN D c E'NOCH P. srEvE'Ns, or MORGAN PARK', ILLINOIS.

EOLLER-GR'ATE.

Specication of Letters Patent.

Patented Feb. 9, 1915.

Application flied May 2o. 1912. serial No. 698.391.

To all 'wko/1L it may conce/rin: Be it known that I.. ENocH P. STEVENS. a citizen of the United States, residing at Morgan Parli, in the county ot' Cool( and State of Illinois, have invented certain new and useful*Improvements 1n Roller-Grates, of which the following is a specification.l

lvl'y invention relates` to roller grat-es and particularly. to grates of this character adapted to operate by gran-ity and mechanically to automatically feedcoal in the stokingl of .locoin'otiif'es andv other furnaces. In such cases it' is important that, during the progressive combustion of the fuel. the same sfh'all be caused to travel. continuouslyfrom the' point oif'xintroduction at the rear of the fire bott to tlievpoint-,of discharge to the'ash pit :it the front ofthe samean`d moreover that the introduction of air to the fuel shallfbe. graduated to the demand in order to" pro-duce perfect combnsti/on,,less being required as the' fuelis more nearly reduced to" ash. lt' vis also found that with the cheaper grades of fuel there is a tendency to coke andl thus impairgor delay the complet'e consumption of the same and cause thegrateto clog or the travellof. the fuel bed` to` become intermittent or to cease entirely at certain points within the fireboxrequiring' iiianual breaking' up and' agitation. Having these objects and conditionsin View Ii arrange; the grate at an' incline' so. afs to 'li'zej the4 action of grav'ityin feeding the ard and I also provide.rotarygrate rece es the fuelfrqm niegloepprecedl A and p'asse'sit onI to thesucceedlngbar, suc-hgrate bars"A being arrangedl toadniit to tfh'efullair in quantities gradually decreas-v ing from' the rear to the front to accord with'thev requirements of progressive l coinbnst'ion. l' also preferably' arrange, in the spaces between the successive grate' bars,

Ill the accoinpanyingdrawi'n'gs fbimiiigfA a partof this' application whifcliref.. y had in .derartiger-1dgaine d'ejseripuea er Athe lSame, r have masa" ted' fence will be tary* 12in-naaien een box ot' a locomotive showing my improved roller grate in side elevation. Fig. 2 is a detail plan view of certain of the grate elements with parts broken away. Fig. 3 is a fragmentary vertical section through a pair of adjacent grate bars and the interposed trip bar. Fig. l is a view showing the same parts as F ig. f3 but in side elevation. Fig. 5 is a. 'View similar to Fig. 2 but of a modification. Fig. G is an iregular longitudinal vertical section through Fig. 5, and Fig. 7 is a detail view showing a further slightly nodiiied form of grate bar.

In the drawings and having more particular reference to Figs. vl to 4 inclusive, reference numeral 11 designates the water space of a boiler having the legs 12 and 13 depending respectively in the rear of and at the front of the lire box 14, Within which Visfarra'nged the brick arch 15 resting upon pipes 16 which establish a. communication between the. legs 12 and 13 through the combustion area. The rear portion. of the Firebox merges into the hopper 17 through which coal is supplied Vand directed by the inclined lower wall 18 upon the grate which latter forms the subject matter of the present application and will now be described in, detail. lAseries of grate bars 19, 20, 21', 22, 23 and 24 are arranged transversely of the fire boX in the lower portion of the saniein spaced tandem relation. as shown and atan inclination from the rear to the t'rontz of the fire box. vThis series ofgrate bars servesv to feed thelfuel. progressively from the' rear to the frontV of the fire boX and to deliver the unconsumed portions to the ash discharge bar 25 which .occupies a position'in line with the fuel grate bars and the extreme front end of the fire box, it being'understood that the number of grate bars may be rincreased or diminished according to the size of the fire box and. the nature of the fuel as conditions may demand., Eachof the .fnel bars comprises a shaftfwhichin its medial portion 2,6 islangularin cross. section,` whileat its end portions.2.7, `2T it is .advantageously circular inrosssection .and journaled in suitable beartheside wallsof thejire box or-in bearing plates 28, 28 built into the tire b ox struture. .Upon the angular portion 26 or.

each of the shafts are disposed a number of unit sectionseach composed. vof, a..pluralitv ofdislrs 29.*spaed apartbylaterallngs 30 s`` asitc provide" a passageway between ad jacent disks for air from the space beneath the grate bars to the fuel area above the same. The spaces between the disks upon the successive shafts gradually decrease from the rear to the front so as to provide a gradually decreasing area for the admission of air, until the last grate bar 24 is reached and this grate bar may be made substantially or entirely solid or impervious to the passage of air, it being, however, also preferably built up of unit sections to facilitate the assembling of the same so as to produce a grate bar of varying length to fit within fire boxes of different widths, and to permit the individual grate bars and single sections to be independently removed and renewed as occasion may require. Immediately in front of the grate bar 24 and operating in close peripheral relation thereto is similarly mounted the ash discharge bar 25 which is provided with radially extending vanes 31. In my preferred construction the grate bars .19-24 are spaced apart suliciently to receive in the interspaces trip bars 32 which are substantially tri-angular in cross section and have their ends iournaled at 33 in the bearing plates 28. These trip bars are provided along their rear edges with a series of tongues 34 which take into the spaces between the disks 29 of the preceding grate bar but do not extend into said spaces far enough to reach the lugs 30. Upon the front edge each of the trip bars 32 is provided with a pair of ribs or shoulders 35, 35 which take into the spaces between the disks of the succeeding grate bar and extend into the path of the lugs 30 so as to contact therewith during the rotation of the grate bar whereby the trip bar will be rocked in its bearings. At its two ends each trip bar is provided with a crank arm 36 to which is attached one end of a coil spring 38. the other end of which is attached to a suitable fixed support. Upon one end of each of the grate bars 1.9 to 24 is mounted a ratchet wheel 39, and a ratchet arm 40 is pivoted upon the end 27 of each shaft. Each of these ratchet arms carries a pawl 41 in operative engagement with the teeth of the ratchet 39. the end of each of the ratchet arms 40 being pivoted at 42 to a crank rod 43 pivoted at 44 to the crank disk 45 which is driven by any suitable source of power and which through the ratchet and pawl mechanism rotaes the grate bars 19 tn 24 in a uniform direction step by step. Upon the opposite end of the grate bar 24. its shaft 27 has keyed thereon a gear 46 which is in mesh with a similar gear 47 keyed to the shaft of the ash discharge bar 25 whereby the bar 25 is caused to partake of the rotar;7 movement of the bar 24 but in the opposite direction.

From the foregoing description it will be `between adjacent grate bars.

readily understood that the step by step ro tary movement of the grate bars 19 to 24 will causethe fuel resting thereon to be fed toward the front of the fire box from each grate bar on to the substantially fiat upper face of the trip bar arranged imi mediately contiguous thereto, the tongues 34 serving to catch any fragments of fuel which may have lodged between the outer edges of the disks. As the grate hars 2O to 24 rotate the lugs 30 thereof will engage the cam face of each of the ribs or shoulders 35 and lift the same rocking the trip bar 32 slowly toward the. fuel being discharged thereon7 such rocking serving at the same time to place the spring 38 under increased tension. As soon as the lug 30 clears the upper edge of the rib 35 the spring 38 will draw the latter quickly downward and rock the trip bar back to its former position imparting to the fuel upon the trip bar a sharp throw toward the front down the incline on to the surface of the next succeeding grate bar, the fuel being thus carried onward by the surface of this grate bar to be discharged on the next trip bar, this operation bein@ repeated intermittently during the step by step rotation of the grate bars. These trip bars 32 serve not only to facilitate the feed of the fuel progressively over the grate but the tripping of the same serves to break up any coal which would otherwise tend to coke and ride intact within the trough formed The tongues 34 and the ribs 35 also not only serve their respective functions as hitherto described but they serve as heat radiating means by which the trip bars are kept cool, a similar function being performed by the lugs 30 between the respective disk which go to make up the unit sections of the grate bars.

In using some kinds of fuel it has been found possible to omit all or a portion of the trip bars 32, in which case the adjacent grate bars are journaled sufficiently close together that the peripheries of the disks are spaced but a slight distance apart, in which case the fuel is fed directly from thev surface of one grate bar on to that of the next succeeding grate bar. Under such circumstances it has also been found to be advantageous to arrange the disks in succeeding grate bars in staggered relation as shown in Fig. 5 so that the under portion of the fuel which upon the one grate bar rested upon the impervious portion of the same will when passing over the next grate bar occupy a position above the spaces between the disks so as to be exposed to the air currents arising therethrough. This staggered relation of the disks may advantageously be employed also in connection with the interposed trip bars although the agitation of the fuel by said bars renders this feature less important in that form of construction and arrangement.

Where the trip bars 32 are omitted it is sometimes found to be advantageous to roughen the peripheries of the disks coniprising the grate bars as indicated in Fig. 7. so as to obviate any tendency of the grate hars to rotate freely beneath the fuel without engaging and carrying the same forward.

ln both forms ol' construction described above the ash discharge bar by its Varies 3l engages the ashes delivered from the grate bar 2l and carries the saine downwardly between the hars 2l and 25 discharging the same in the ash pit beneath the fire box. This ash discharge bar 25 operates in such close relation to the bar 24 and to the front wall of the fire box as to practically exclude the entrance of the air to the front of the fire box from below the saine.

lVhile l have described with a considerable degree of particularity the various features entering into an illustrated einbodinient of the invention in order that the iniention might be readily understood, it will be obvious that still further modifications may be made without departing from the invention or sacrificing its material advantages.

l claim` l. ln a grate, a series of fuel bars coining disk-like sections spaced apart lat-- lly by interposed lugs, the successive bars of the series having their disk sections approached more nearly together to gradually reduce the air passage therebetween, a series of trip bars arranged in the interspaces between the fuel bars. the trip bars having along one edge tongues taking into the spaces between the disks of the preceding fuel and along their opposite edge shoul- Ylass haring a lower cam face extending between the spacing lugs of the next succeedine fuel bar, yielding ineans tending to tilt the trip bars toward the front of the grate, and uieans to rotate the fuel bars step by step in a common direction to feed the fuel from each of said bars on to the upper face of the next succeeding trip bar and toward the front of the grate. the lugs of the fuel bars engaging the lower cani face of the shouland tilting the trip bars in an opposite direction. the yielding means serving to rock the trip bars sharply when released to throw the fuel therefrom on to the next succeeding grate bar. substantially as described.

i?. ln a grate, a series of fuel bars comprising disk-like sections spaced apart laterally by interposed lugs. the successive bars of the series having their disk sections approached more nearly together to gradually reduce the air passage therebetween, a series of trip bars arranged in the interspaces between the fuel bars, the trip bars having along their rear edge tongues taking into the spaces between the disks of the preceding fuel ba r and along their front edge shoulders having a lower cam face extending between the spacing lugs of the next succeeding fuel bar, yielding means tending to tilt the trip bars toward the front of the grate, means to rotate the fuel bars step by step in a common direction to feed the fuel from each of said bars on to the upper face of the nent succeeding trip bar and toward the front of the grate, the lugs of the fuel bars engaging the lower cam face of thc shoulders and tilting the trip bars in an opposite direction. the yielding means serving to rock the trip bars sharplv when released to throw the fuel therefrom on to the next succeeding grate bar, an ash discharge b: ar` ranged parallel and closely adjacent to the last grate bar and provided with radial vanes, and means to rotate said ash dischar;,;'e bar in a direction opposite to that of the fuel bars. substantially as described.

3. In a grate, a series of fuel )ars journaled in successive parallel spaced relation. a ratchet wheel fixed upon one end of each of the bars. a ratchet arln pivoted conceir trically of cach ratchet wheel. a pawl can ried by the ratchet arm in engagement with the teeth of its ratchet wheel. a crank rod connecting the free ends of the several ratchet arins. a suitably driven crank mein-- bei' connected to the crank rod. a series of trip ba journaled in the spaces between the fuel bars, a crank arm carried by cach trip oar, a spring secured to said crank arni and to a suitable support, and means carried b v the fuel bars to rock the trip bars in oppo sition to the spring, whereby the fuel bars are driven step by step in unison and the trip bars sharply rocked at intervals by the tenw sion of their springs. substantially as de scribed.

l. ln a grate, a series of fuel bars journaled in successive parallel spaced relation, a ratchet wheel fixed upon one end of each of the bars. a ratchet ai ni pivoted concentrically of each ratchet wheel, a pawl carried by the ratchet arm in engagement with the teeth of its ratchet wheel, a crank rod connecting the free ends of the several ratchet arms, a iitably driven crank member connected to the crank rod. a series of trip bars journaled in the spaces between the fuel bars. a crank arin carried by cach trip bar, a spring secured to said crank arm and to a suitable support. means carried by the fuel bars to rock the trip bars in opposition to the spring, whereby the fuel bars are driven step by step in unison and the trip bars sharply rocked at intervals by the tension of their springs, an ash discharge bar jour naled in parallel relation to the frontmost of the fuel bars and provided with radial vanes revolving closely adjacent to the periphery of said fuel bar, the frontmost fuel oar and ash discharge bar provided with in termeslling gears whereby the ash discharge bar is rotated in a direction opposite to that ot' the fuel bars, substantially as described.

I. ln a grate, a series of fuel bars co1nprising disk-like sections spaced apart lat erally by interposed lugs, a series of trip bars arranged in the interspaces between the fuel bars, the trip bars having along their front edge shoulders having a lower cam face extending between the spacing lugs of the next succeeding fuel bar, yielding means tending to tilt the trip bars toward the front of the grate, and means to rotate the fuel haw` step by step in a common direction to feed the fuel from ecah of said liars en to the upper face of the next sucfeeding trip bar and toward the front of the grate, the lugs of the fuel bars engaging the lower cani face of the shoulder and tilting the trip bars in an opposite direction. the yieleding means serving to rock the trip hars sl? rply when released to throw the l`uel therefrom on to the next succeeding grate bar. sulifstantially as described.

(i. In a grate. a series of fuel bars coinprising disleli e sections spaced apart lat erally by interposed lugs7 a series of trip bars arranged in the interspaces between the fuel bars, the trip bars having along their rear edge tongues taking into the spaces between the disks of the preceding l'nel bar and along their front edge shoulders having a lower cani face extending between the spacing lugs of the next sue ceeding fuel bar, yielding means tending to tilt the trip bars toward the front of the grate, means to rotate the fuel bars step by step in a coniinon direction to feed the fuel frein each of said bars on to the upper face of the next succeeding trip bar and toward the front of the grate, the lugs of the fuel bars engaging the lower earn face of the shoulders and tilting the trip bars in an opposite direction, the yielding means serving to rccli the trip bars sharply when reO leased to throw the fuel therefrom on to the next succeeding grate bar, an ash discharge bar arranged parallel and closely adjacent to the last grate bar and provided with radial vanes, and means to rotate ash li sarge bar in a direction opposite to that of the fuel bars. substantially as described.

T. ln a grate, a series of fuel bars, each of which comprises a plurality of circular, disk-like sections laterally spaced apart from each other, ineans for rotating said l'uel bars, a series of trip hars arranged in the spaees between the fuel bars, each of said trip bars having a plurality of tongues extending into the spaces between the disk-like seeticns of said fuel bars, a cani on each of said trip bars, lugs on said fuel bars adapted to engage the cams of said trip hars at predetermined points in the rotation of said fuel bars, and a spring attached to each of said trip bars, whereby, when the rain of each trip bar released from the ,ing of the adjacent fuel bar, said trip bar will be. sharply rocked and will advance fuel frein one fuel bar to the next.

ENOCH P. STEVENS.

lVitnesses Lnwis T. (uiiis'r, LUTHnn JOHNS.

Copies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents.

Washington, D. C. 

